core: move get_distance() from divesite.cpp to units.cpp

This gives the distance between to location_t objects. It is
unclear why this was in divesite.cpp.

Moreover pass by value, not raw pointer.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/divesite.cpp

@@ -50,32 +50,14 @@ dive_site *dive_site_table::get_by_gps_and_name(const std::string &name, const l
 									     ds->name == name; });
 }
 
-// Calculate the distance in meters between two coordinates.
-unsigned int get_distance(const location_t *loc1, const location_t *loc2)
-{
-	double lat1_r = udeg_to_radians(loc1->lat.udeg);
-	double lat2_r = udeg_to_radians(loc2->lat.udeg);
-	double lat_d_r = udeg_to_radians(loc2->lat.udeg - loc1->lat.udeg);
-	double lon_d_r = udeg_to_radians(loc2->lon.udeg - loc1->lon.udeg);
-
-	double a = sin(lat_d_r/2) * sin(lat_d_r/2) +
-		cos(lat1_r) * cos(lat2_r) * sin(lon_d_r/2) * sin(lon_d_r/2);
-	if (a < 0.0) a = 0.0;
-	if (a > 1.0) a = 1.0;
-	double c = 2 * atan2(sqrt(a), sqrt(1.0 - a));
-
-	// Earth radius in metres
-	return lrint(6371000 * c);
-}
-
 /* find the closest one, no more than distance meters away - if more than one at same distance, pick the first */
-dive_site *dive_site_table::get_by_gps_proximity(const location_t *loc, int distance) const
+dive_site *dive_site_table::get_by_gps_proximity(location_t loc, int distance) const
 {
 	struct dive_site *res = nullptr;
 	unsigned int cur_distance, min_distance = distance;
 	for (const auto &ds: *this) {
 		if (dive_site_has_gps_location(ds.get()) &&
-		    (cur_distance = get_distance(&ds->location, loc)) < min_distance) {
+		    (cur_distance = get_distance(ds->location, loc)) < min_distance) {
 			min_distance = cur_distance;
 			res = ds.get();
 		}

core/divesite.h

@@ -51,11 +51,10 @@ public:
 	dive_site *get_by_name(const std::string &name) const;
 	dive_site *get_by_gps(const location_t *) const;
 	dive_site *get_by_gps_and_name(const std::string &name, const location_t *) const;
-	dive_site *get_by_gps_proximity(const location_t *, int distance) const;
+	dive_site *get_by_gps_proximity(location_t, int distance) const;
 	void purge_empty();
 };
 
-unsigned int get_distance(const location_t *loc1, const location_t *loc2);
 struct dive_site *unregister_dive_from_dive_site(struct dive *d);
 struct dive_site *get_same_dive_site(const struct dive_site &); // accesses global dive list
 std::string constructLocationTags(const taxonomy_data &taxonomy, bool for_maintab);

core/parse-xml.cpp

@@ -1197,7 +1197,7 @@ static void gps_in_dive(const char *buffer, struct dive *dive, struct parser_sta
 	parse_location(buffer, &location);
 	if (!ds) {
 		// check if we have a dive site within 20 meters of that gps fix
-		ds = state->log->sites->get_by_gps_proximity(&location, 20);
+		ds = state->log->sites->get_by_gps_proximity(location, 20);
 
 		if (ds) {
 			// found a site nearby; in case it turns out this one had a different name let's

core/units.cpp

@@ -180,3 +180,22 @@ const struct units *get_units()
 {
 	return &prefs.units;
 }
+
+// Calculate the distance in meters between two coordinates.
+unsigned int get_distance(location_t loc1, location_t loc2)
+{
+	double lat1_r = udeg_to_radians(loc1.lat.udeg);
+	double lat2_r = udeg_to_radians(loc2.lat.udeg);
+	double lat_d_r = udeg_to_radians(loc2.lat.udeg - loc1.lat.udeg);
+	double lon_d_r = udeg_to_radians(loc2.lon.udeg - loc1.lon.udeg);
+
+	double a = sin(lat_d_r/2) * sin(lat_d_r/2) +
+		cos(lat1_r) * cos(lat2_r) * sin(lon_d_r/2) * sin(lon_d_r/2);
+	if (a < 0.0) a = 0.0;
+	if (a > 1.0) a = 1.0;
+	double c = 2 * atan2(sqrt(a), sqrt(1.0 - a));
+
+	// Earth radius in metres
+	return lrint(6371000 * c);
+}
+

core/units.h

@@ -132,6 +132,7 @@ typedef struct pos {
 } location_t;
 
 extern void parse_location(const char *, location_t *);
+extern unsigned int get_distance(location_t loc1, location_t loc2);
 
 static inline bool has_location(const location_t *loc)
 {

desktop-widgets/locationinformation.cpp

@@ -390,7 +390,7 @@ bool DiveLocationFilterProxyModel::lessThan(const QModelIndex &source_left, cons
 		// The dive sites are -2 because of the first two items.
 		auto loc1 = (*divelog.sites)[source_left.row() - 2]->location;
 		auto loc2 = (*divelog.sites)[source_right.row() - 2]->location;
-		return get_distance(&loc1, &currentLocation) < get_distance(&loc2, &currentLocation);
+		return get_distance(loc1, currentLocation) < get_distance(loc2, currentLocation);
 	}
 	return source_left.data().toString().compare(source_right.data().toString(), Qt::CaseInsensitive) < 0;
 }

desktop-widgets/modeldelegates.cpp

@@ -478,7 +478,7 @@ void LocationFilterDelegate::paint(QPainter *painter, const QStyleOptionViewItem
 		if (ds->location == currentLocation) {
 			bottomText += tr(" (same GPS fix)");
 		} else {
-			int distanceMeters = get_distance(&ds->location, &currentLocation);
+			int distanceMeters = get_distance(ds->location, currentLocation);
 			QString distance = distance_string(distanceMeters);
 			size_t nr = ds->nr_of_dives();
 			bottomText += tr(" (~%1 away").arg(distance);

qt-models/divelocationmodel.cpp

@@ -298,7 +298,7 @@ bool GPSLocationInformationModel::filterAcceptsRow(int sourceRow, const QModelIn
 		return false;
 
 	return distance <= 0 ? ds->location == location
-			     : (int64_t)get_distance(&ds->location, &location) * 1000 <= distance; // We need 64 bit to represent distances in mm
+			     : (int64_t)get_distance(ds->location, location) * 1000 <= distance; // We need 64 bit to represent distances in mm
 }
 
 GPSLocationInformationModel::GPSLocationInformationModel(QObject *parent) : QSortFilterProxyModel(parent),

qt-models/divesiteimportmodel.cpp

@@ -67,7 +67,7 @@ QVariant DivesiteImportedModel::data(const QModelIndex &index, int role) const
 		case NEAREST: {
 			// 40075000 is circumference of the earth in meters
 			struct dive_site *nearest_ds =
-				divelog.sites->get_by_gps_proximity(&ds->location, 40075000);
+				divelog.sites->get_by_gps_proximity(ds->location, 40075000);
 			if (nearest_ds)
 				return QString::fromStdString(nearest_ds->name);
 			else
@@ -76,10 +76,9 @@ QVariant DivesiteImportedModel::data(const QModelIndex &index, int role) const
 		case DISTANCE: {
 			unsigned int distance = 0;
 			struct dive_site *nearest_ds =
-				divelog.sites->get_by_gps_proximity(&ds->location, 40075000);
+				divelog.sites->get_by_gps_proximity(ds->location, 40075000);
 			if (nearest_ds)
-				distance = get_distance(&ds->location,
+				distance = get_distance(ds->location, nearest_ds->location);
-					&nearest_ds->location);
 			return distance_string(distance);
 		}
 		case SELECTED: